Electronic conductivity in the SiO2-PbO-Fe2O3 glass containing magnetic nanostructures
PBN-AR
Instytucja
Wydział Fizyki Technicznej i Matematyki Stosowanej (Politechnika Gdańska)
Informacje podstawowe
Główny język publikacji
ENG
Czasopismo
SOLID STATE IONICS
ISSN
0167-2738
EISSN
Wydawca
DOI
URL
Rok publikacji
2014
Numer zeszytu
1
Strony od-do
801-805
Numer tomu
262
Identyfikator DOI
Liczba arkuszy
Słowa kluczowe
CONDUCTION MECHANISM
IMPEDANCE SPECTROSCOPY
IRON-OXIDE GLASS
NANOSTRUCTURES
UNIVERSAL DIELECTRIC RESPONSE
Streszczenia
Język
Treść
The linear impedance spectra of iron–silicate–lead glass samples were measured in the frequency range from 1 MHz to 1 MHz and in the temperature range from 153 K to 423 K. The structure was investigated by means of XRD and atomic force microscopy. Local electrical and magnetic properties of the samples were tested with the aid of electrostatic force microscopy (EFM) and magnetic force microscopy (MFM). The obtained results show that the impedance spectra of all samples exhibit one large relaxation process and some additional small relaxation is present in glass containing 20 mol% and 25 mol% Fe2O3. The AFM micrographs show that in a subset of samples some nanostructures exist. Their size, shape, and quantity depend on the amount of Fe2O3 in the composition of the glass. The samples containing an amount of 15 mol% of Fe2O3 include the biggest nanostructures which are ball-shaped. EFM and MFM micrographs show that nanostructures exhibit different electrical and magnetic behaviors than the rest of the glass matrix. On the basis of Jonscher universal dielectric response the temperature dependence of conductivity exponent s was determined and compared to theoretical models proposed by Elliott. It was found that while in the glass containing less than 15 mol% iron oxide, there is only one process responsible for conduction mechanism, the overlap polaron tunneling. In the other samples, a different conduction mechanism may coexist: quantum mechanical tunneling between semiconducting granules.
Inne
System-identifier
128558